When stackforge_libs is enabled, the WSME and Pecan libraries
are checked out from stackforge and installed from source instead of
pip. This change introduces a new function to perform the installation
without attempting to sync the global requirements list, since the
version of setup.py in the global requirements repository breaks the
dependencies for WSME (there is no ipaddr library in python 2, so we
need to install it, but under python 3 where it is part of the stdlib we
cannot include it in the requirements).
Fixes bug 1252488
Change-Id: I58357757ac67a919bf70178b76f65fa0a9e16242
wsme and pecan libraries have migrated to stackforge for
development. If we support them in devstack, we can use their git
version instead of the release version, which ensures that they
won't break the rest of OpenStack when they cut a new release.
This is similar to how oslo testing works. Long term we probably
want a more generic mechanism to handle this, but for now, this
should get us rolling, and get them gating.
Change-Id: Icf3475f433081c7c625864107d7e118e214396e1